Process for the production of homogeneous wood material and the product thereof



Patented Aug. 28, 1923.

UNITED STATES 1,465,937 PATENT OFFICE.

VILLEHAD HENBIK FORSSMAN, OF COLOGNE, GERMANY.

PROCESS FOR THE PRODUCTION OF HOMOGENEOUS WOOD MATERIAL AND THE PRODUCT THEREOF.

No Drawing. Continuation of application Serial No. 593,650, filed October 10, i922. This application flied March 31, 1923. Serial No. 629,172.

I '0 all whom it may concern:

Be it known that I, VILLEHAD HENRIK FoRssMAN, a subject of the King of Sweden, residing at Cologne, Germany, have inventcd certain new and useful Improvements in Processes for the Production of Homogeneous Wood Material and the Product Thereof, of which thefollowing is a specification, the same being a continuation of my application entitled Process for the production of practically homogeneous wood material and wood bodies and the product thereof, filed October 10, 1922, Serial Number 593,650.

The objects of this invention are to pro vide aprocess for the production of homogeneous wood material, which may also be substantially free from tendencies towards deformation caused by variations in temperature o'r humidity, by reason of the treatments described and claimed in my copending application entitled Process for the treatment of wood material and the product thereof, executed on even date herewith, and also to provide a wood-material with new and very valuable characteristics. The process hereinafter described for rendering wood material homogeneous is preferably employed after the treatment set forth in said application, although it may be independently utilized to advantage.

lVood material consists principally of fibres and superposed arid interposed cells. The inner spaces of these cells enclose hygroscopic substances, whose changing degrees of humidity tend to cause inner tensions in the wood material and consequent deformations. There are also within the cells albumen or ferment substances which tend to putrefy, this affecting the form and characteristics of the wood material.

The invention of my process consists broadly in treating a thin layer of wood with a cellulose solution, such as acetylcellulose in acetone, said layer having preferably a substantial number of its cells mechanically opened and preferably having had the contents of said cells rendered nonhygroscopic and non-fermentable.

The wood material to be treated is first separated into one or more thin layers by suitable mechanical methods, such as by cutting, slicing, etc. If every cell is opened so that its contents can be treated, theoretical perfection will be attained, but it is unnecessary as well as usually impracticable to strive for such accuracy. In the case of woods of central Europe, I have obtained remarkable results with layers of about a tenth of a millimetre thickness, in which layers most of the cells were exposed, but it is not necessary to employ such very thin layers in the use of my process, as thin layers of wood materials of two and a half millimetres thickness can be successfully treated by my process.

The reason therefore is that the cellulose solution which is applied to the thin layer penetrates it more thoroughly in proportion to the number of opened cells. The impregnation of one or more thin layers by a cellulose solution has the extremely valuable effect of filling the interstices and opened cells with a solution having s bs antially the inherent properties and characteristics of the wood material itself, thus producing a sub stantially homogeneous material, which is peculiarly adapted for working and for the production of such wooden articles as boxes, trunks, canoes, automobile bodies, etc.

Preferably, I first subject the thin layer to one or more of the treatments set forth in my said application, to which reference is here made. but 'which treatments may be briefly described as follows, namely, as consisting broadly in suitably treating the contents of as large a number as practicable of these cells, the maximum results being obtained by mechanically opening as many as possible, either by washing out the hygroscopic and ferment substances therein or by treating them with a suitable neutralizing solution, as for example, one containing chrome alum with or without formaldehyde, or by washing and then neutralizing the undesirable hygroscopic and ferment qualities of the cell contents.

Thin wood layers when treated as above described become soft and'pliable, so that superposed layers may be readily shaped by merely stretching over a core or placing in a mould. The application of heat and pressure or either may be employed to facilitate the described treatment. During the treatment. the treated layers expand and swell considerably, there being a correspondingly great contraction upon drying, which has the effect of causing to disappear during drying any folds occuring during the expanding and swelling, of the material. Wood material treated by my process possesses the very valuable characteristics of being substantially immune from deformations caused by variations in temperature and humidity as encountered during usage. If desired, it can be subsequently treated with suitable solutions for the purpose of altering its shape.

The advantages of prior treatment by one or both of the processes of my said application are that the homogeneous wood material will not warp, contract or otherwise change its form when exposed to usage conditions.

I claim:

1. The process of treating a thin layer of wood material, compri'singimpregnating it with a cellulose solution.

2. The process of treating a thin layer of wood material, comprising impregnating it with a solution containing acetylcellulose acetone.

3. The process of treating a thin layer of wood material, a substantial number of whose cells have been opened, comprising impregnating it with a solution containing acetylcellulose acetone.

4. The process of treating a thin layer of wood material comprising the subjection of the contents of a substantial number of its cells to a solution adapted to neutralize the hygroscopic and ferment qualities of substances in said cells, and impregnating said layer with a cellulose solution.

5. The process of treating a thin layer of wood material, comprising the washing out of hygroscopic and ferment substances from a substantial number of its cells and impregnating said layer with a cellulose solution. i

6. \Vood materiaLand cellulose matter in a substantially homogeneous thin layer.

7. Wood material and cellulose matter in a substantially-homogeneous thin layer, a substantial number of Whose cells are substantially free from hygroscopic and ferment substances.

In testimony-whereof I hereunto aflix my signature in the presence of two witnesses.

VILLEHAD HENRIK FORSSMAN. Witnesses:

GEo. Rosswao,

HENRY W. Hnnns. 

